In one form of prior art hose coupling a nipple has a generally tubular exterior at one end to extend into a flexible hose, an enlarged head at the other end formed to be clamped against a part to which the hose is to be connected, a nut over the head and having an inturned flange to engage a shoulder on the head for clamping the head against the part, and has an external thread between the extension and head for threaded attachment to a socket that clamps the hose against the nipple extension. The nut flange has a bore larger than the major diameter of the external thread so that the nut may be slipped over the extension and thread of the nipple before the socket is threaded to the nipple.
In some cases the nipple is put into stock without the socket assembled thereto because the nipple may be usable with several sizes of sockets, depending on the type of hose to be used, or the socket may be of the reusable type in which it is assembled to the hose first and the nipple is then inserted into the hose and threaded to the socket. In such cases it may be desirable to have the nut assembled to the nipple while in inventory. However, with prior art couplings as just described the nut could easily separate from the nipple while the socket is not attached to the nipple. Also, when assembling the socket to the nipple the nipple and nut must be handled as a two-piece part so that care must be taken so that the nut does not separate from the nipple just prior to threading of the socket onto the nipple.